Coronavac, one of the vaccines developed within the scope of combating the COVID-19 pandemic that has surrounded the world for a year, started to be applied in the first healthcare workers in our country. In this important step taken to end the pandemic, information on vaccines is still limited. Most vaccines, including the Coronavac vaccine, are applied with approval for emergency use before phase 3 studies are fully completed. While investigating the effect of the vaccine on the virus, possible side effects should also be considered. In this context, it is not known whether the vaccine has an effect on the menstrual cycle, especially of women of reproductive age.

Our primary aim in our study is to evaluate the effect of the vaccine on the menstrual cycle and if the vaccine has any effect on the menstrual cycle, what kind of changes this effect causes.

The survey contains 20 questions aimed at obtaining information about the menstrual cycles of health workers before and after vaccination. Demographic data of the participants are also taken.

Inclusion Criteria:

• be positive for covid-19 (severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 )
• Having 1 or 2 doses of vaccine
• have menstruation
• Being a female health worker
• not using drugs that can affect menstruation

Exclusion Criteria:

• be negative for covid-19(severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 )
• have no menstruation
• Being a male health worker

It includes female healthcare workers between the ages of 8 and 45. For participation, 1 or 2 doses of vaccine should be administered and at least one menstrual period after the match.